Mad Men creator Matthew Weiner opened up during a Lionsgate-sponsored panel Wednesday at the Television Academy theater in North Hollywood that also featured cast members Jon Hamm, Elizabeth Moss, John Slattery, Robert Morse, Jared Harris, Kiernan Shipka and others. (We’re getting closer to the June Emmy balloting period.) Amy Dawes reports:

The news that two new shows steeped in early ‘60s style and social mores have made the networks’ fall lineup was not lost on Matthew Weiner. “For them to see that there’s some commercial potential in this area, four years after we got it going – that’s pretty brave,” he said sardonically, referring to ABC and NBC, which have picked up Pan Am and The Playboy Club, respectively.

Weiner also revealed that he already knows how he’ll end his much-lauded series, set in the Madison Avenue advertising world of the ‘60s – and he’s always known. “I just didn’t know if I’d have one episode to do it in or 20,” he said.

Now, he knows exactly how much storytelling real estate he has – thanks to recent negotiations with AMC that resulted in a contract for 39 more episodes of the Lionsgate-owned drama with Weiner at the helm. The show returns in March 2012, Weiner said, for three seasons of 13 chapters each. Each episode will be released in two lengths – a 45-minute version for airing on AMC, and a longer version that will appear eight days later for release to digital media platforms and DVD. “Maybe people will watch both,” he said. “Everybody won as far as I’m concerned.”

Mad Men has been absent from the airwaves since mid-October, when its fourth season finale aired on AMC. “We opened the writers’ room yesterday and we’re facing the blank page again,” said Weiner. He confirmed that season five on the show, which hews closely to historic and cultural events of the tumultuous ‘60s, will involve a forward jump in time – but didn’t give further details.

“You only hope, as an actor, that we’ll be able to land this plane as successfully as we took off with it,” said leading man Hamm. He added: “I wouldn’t want to trade places with Matt, because he’s under such pressure to match what he achieved in previous seasons.”

“It’s not because of the hair thing?” quipped Weiner, who’s nearly bald.

Cast members discussed the many gradations of inebriation required of actors such as Hamm and Slattery. Though vice is a way of life at the ad firm, “there are no real cigarettes and no real drinking on our sets,” said Weiner. “A martini on our set is a glass of water with an onion in it. It’s delicious – you should try it sometime.”

The event included a screening of the The Suitcase, a season four episode focusing on one epic, stressful night in which Peggy (Moss) breaks up with her boyfriend, has a heated, humiliating confrontation with her boss (Hamm), and then pulls an all-nighter of working and drinking with him. By morning, the show hints that the two workaholics are beginning to recognize each other as soul-mates, and possibly more.

Weiner wouldn’t divulge where the storyline is going. But given the show’s remarkable record of acclaim – it’s won the Emmy for outstanding drama series three times straight, among many other awards – he came across as surprisingly humble. “Being here at the TV Academy with this cast, and having people ask what’s going to happen on the show – it feels surreal,” he says. “This is a dream come true, and all the cliches about doing a job you love are true.”

Watch Don bring Peggy to tears in this scene from The Suitcase episode of Mad Men: